SEATTLE -- American business travelers continue to use the Internet to book travel, but many still use offline services when making itinerary changes, according to a new survey of American business travelers with online access.

Travelport Corporate Solutions, a Cendant Corp. subsidiary that provides corporate travel management services, commissioned the survey. Conducted by Harris Interactive, the survey found that although more than half (52%) of American business travelers book their business travel online, one-third (33%) still use offline channels such as traditional travel agents to make or amend reservations.

The number of companies offering online self-booking as part of their corporate travel programs continues to grow, but many employees are not taking advantage of more efficient, less expensive online tools, Travelport said.

In the survey, Travelport measured American business travelers' opinion of booking options and examined the reasons why travelers choose more expensive offline services. Results point to the options valued by business travelers and suggest the type of online or automated features needed to ensure traveler satisfaction while maintaining savings.

Survey results identified key reasons why American business travelers using online booking services also access offline services:

* The desire to have a person confirm what is booked online (49%)

* While on the road or at the last minute, it's too difficult to update plans online (32%)

* Online booking cannot address some specific travel needs (29%).

"Online self-booking delivers savings for corporate travel, but this survey identifies specific situations when business travelers prefer to go offline, thereby negating a portion of those savings," said Charlotte Blackwell, vice president of product and marketing for Travelport. "With up to a third of travelers choosing to go offline, this suggests travel management companies must provide faster and easier-to-use online and automated options that instill confidence in the user while meeting their real-world needs. Innovation through technology will ultimately maximize savings and efficiency."